Watch: Road Sign Crashes Down on Car on Melbourne Freeway

Heart-stopping footage has emerged showing the moment a road sign crushed a car on a Melbourne freeway, 9News reports.

The video shows just how lucky the driver was to escape the incident with her life. The 54-year-old Australian woman was driving along Tullamarine Freeway yesterday at around 5.30pm when the sign came loose.

An investigation will look at all signs installed at similar time along the freeway.